I'm not arguing about the use of meval internal to Maxima. I think it is a mistake to use the maxima command ev(...) unless there is no alternative.
ev() as has been pointed out, evaluates expressions to symbols in different and unexpected scopes sometimes.
I can't test it now (I'm travelling) but resimplification should be possible after a subst, if necessary, by simplify().
RJF
----- Original Message -----
From: Michel Van den Bergh <michel.vandenbergh at uhasselt.be>
Date: Tuesday, January 16, 2007 3:22 pm
Subject: Re: [Maxima] Unsimplification???
> Robert Dodier wrote:
>
> > On 1/16/07, Michel Van den Bergh
> <michel.vandenbergh at uhasselt.be> wrote:
> >
> >> Maybe I should give the specific problem I was looking at.
> >> The model is an expression (i.e. bfloat(t)) in which you substitute
> >> values for certain variables and then you want to
> >> "evaluate it" to get a numeric result, if possible. How to do this
> >> without invoking ev?
> >
> >
> > I guess I don't understand the point of avoiding MEVAL.
> > That is not something I would recommend to users,
> > and it's not clear to me why it was recommended to you.
>
> I assume Richard will explain this since this is his opinion.
> Certainly explicitly calling ev is tricky since evaluation may
> happen in
> the wrong scope
> (I struggled with this in levin). I.e. the expression given by the
> user
> may contain names of local variables
> or parameters. In his earlier emails Richard seemed to impy that
> one
> could get by without ev and
> replace it by substitution. I was just testing this.
>
> Michel
>
>
>
>
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